Adaptive signal processing systems, such as adaptive array antennas, may employ several thousand complex weights for steering an antenna beam (or beams). In microwave communication systems, in which a number of different elements are combined to meet the functional demands of the system, component fabrication has taken the form of monolithic microwave integrated circuits (MMICs) which offer low cost, miniaturization and high reliability. In such circuits, semiconductor material such as gallium arsenide, indium phosphide and other III-V components make it possible to integrate a large number of signal processing elements to meet the needs of the system. One type of signal processing component which has enjoyed use in complex weight networks in such systems is the field effect transistor. Typically the application of FETs to attenuator networks has involved dual-gate FETs as variable gain elements or single-gate FETs arranged in conventional "L", "T", and "PI" configurations. Now although these FET attenuator circuits are capable of providing a substantial degree of controlled attenuation of an input signal, they also introduce a significant phase shift. As a result such devices are not practically suited for a number of signal processing applications, such as adaptive null steering array systems, wherein the null depth is limited by the phase shift variation versus attenuation in the complex weight.